Toggle dispensing closures have been used on dispensing packages for many years. One such closure is described in U.S. Pat. No. 3,516,581 issued to Micallef on Jun. 23, 1970, which is hereby incorporated herein by reference. Typically the closure is formed from a cap member, to seal the top of the package, and a toggle closure secured onto the top of the cap. The toggle is so that by pressing down on one end of the toggle, the other end moves up so as to expose a dispensing opening which communicates with the interior of the package so as to dispense the product, typically a liquid product. Thereafter, in order to close the toggle, the end of the toggle having the dispensing opening therein is pressed down so as to return the toggle to its original closed position.
Most toggles, including the one disclosed in the Micallef reference, are retained onto the package through use of semi-spherical pins or projections extending from the sides of the toggle. These pins snap into a pair of corresponding semispherical indentations on the cap so as to retain the toggle and allow it to pivot. However, the semi-spherical snap-on arrangement described above does not securely retain the toggle onto the cap, and can become dislodged. One type of toggle closure which does not have the toggle attached to the cap by way of semi-spherical indentations is described in U.S. Pat. No. 5,242,079 issued to Stephens et al. on Sep. 7, 1993, which is hereby incorporated herein by reference. As seen in FIG. 4 of that reference, the toggle appears to be retained onto the closure through the use of apertures on the cap which cooperate with journals on the toggle.
However, when both of these types of closures are manufactured using injection molding, the semi-spherical indentations or apertures on the cap are typically created through the use of a complex mechanism, such as a core pull, which is within the stationary half of the injection mold. That is, a separate moving piece of machinery is needed to create the semi-spherical indentation or aperture. This method of manufacture is undesirable in that significant capital expenditure is incurred in purchasing and maintaining these mechanisms. Moreover, the cost of the molded parts is increased due to the longer cycle times involved in cooling a mold having a complex mechanism.
There has, therefore, been a desire to have a toggle dispensing closure which can be manufactured in one injection molding step and overcome the downfalls of the previously described method.
There has also been a desire to have a toggle dispensing closure which can be manufactured using injection molding but without the use of a complex mechanism.
There has also been a further desire to have such a closure which will not easily break or scratch when removed from the mold.
There has also been a desire to have such a closure where the toggle is securely retained onto the cap.